Question 1

An advantage of an electrical synapse over a chemical synapse is that

Accepted Answer

A)  transmission is fast. 
B)  the short distance between cells allows rapid temporal summation. 
C)  an electrical synapse requires minimal cell-to-cell contact. 
D)  cells generally have more connexins than receptors. 
E)  they are useful in rapid communication and learning. 
A)  transmission is fast. 
B)  the short distance between cells allows rapid temporal summation. 
C)  an electrical synapse requires minimal cell-to-cell contact. 
D)  cells generally have more connexins than receptors. 
E)  they are useful in rapid communication and learning.

Question 2

Evaluate the following statement: Normally an action potential is propagated in two directions, toward the cell body and away from the cell body.

Accepted Answer

The statement is incorrect. Typically ac

Question 3

An action potential arriving at an axon terminal may cause release of a chemical messenger call a(n) _______.

Accepted Answer

The answer of An action potential arriving at an axon...

Question 4

Botulinum toxin impairs muscle contraction by acting on proteins that anchor vesicles in the presynaptic membrane.The toxin has medical uses.Given its effects at the neuromuscular junction, botulinum could be used to treat all of the following except

Accepted Answer

A)  eyelid twitches. 
B)  jaw clenching. 
C)  facial tics. 
D)  flaccid arm and leg muscles. 
E)  muscle spasms of cerebral palsy. 
A)  eyelid twitches. 
B)  jaw clenching. 
C)  facial tics. 
D)  flaccid arm and leg muscles. 
E)  muscle spasms of cerebral palsy.

Question 5

Giant neurons involved in the escape response of crayfish have _______ synapses, which allow rapid signal transmission.

Accepted Answer

The answer of Giant neurons involved in the escape response...

Question 6

Information about a sensory stimulus such as touch can be prevented from reaching the central nervous system by chemically blocking

Accepted Answer

A)  touch receptors in the central nervous system. 
B)  afferent neurons from the sensory cells detecting touch. 
C)  graded potentials in interneurons. 
D)  efferent neurons carrying information to the spinal cord. 
E)  neurotransmitter release from interneurons in the brain. 
A)  touch receptors in the central nervous system. 
B)  afferent neurons from the sensory cells detecting touch. 
C)  graded potentials in interneurons. 
D)  efferent neurons carrying information to the spinal cord. 
E)  neurotransmitter release from interneurons in the brain.

Question 7

Temporal summation adds up postsynaptic potentials that

Accepted Answer

A)  occur at the same time at different locations on the postsynaptic neuron. 
B)  are generated at regular intervals. 
C)  cause the same amount of depolarization in the axon hillock. 
D)  are generated at the same site in rapid sequence. 
E)  cause a hyperpolarization of the cell membrane. 
A)  occur at the same time at different locations on the postsynaptic neuron. 
B)  are generated at regular intervals. 
C)  cause the same amount of depolarization in the axon hillock. 
D)  are generated at the same site in rapid sequence. 
E)  cause a hyperpolarization of the cell membrane.

Question 8

Diseases that destroy myelin

Accepted Answer

A)  also destroy astrocytes. 
B)  are restricted to the central nervous system. 
C)  can be cured. 
D)  also destroy tripartite synapses. 
E)  impair conduction of action potentials. 
A)  also destroy astrocytes. 
B)  are restricted to the central nervous system. 
C)  can be cured. 
D)  also destroy tripartite synapses. 
E)  impair conduction of action potentials.

Question 9

Which of the following represents the correct order of the parts of neurons that are involved in the flow of information, beginning with the presynaptic cell and ending where a synapse is made with a postsynaptic cell?

Accepted Answer

A)  Dendrites, cell body, axon hillock, axon, axon terminals 
B)  Cell body, axon terminals, axon hillock, axon, dendrites 
C)  Axon, cell body, dendrites 
D)  Axon terminals, axon hillock, cell body, dendrites 
E)  Synapse, axon, cell body, dendrites 
A)  Dendrites, cell body, axon hillock, axon, axon terminals 
B)  Cell body, axon terminals, axon hillock, axon, dendrites 
C)  Axon, cell body, dendrites 
D)  Axon terminals, axon hillock, cell body, dendrites 
E)  Synapse, axon, cell body, dendrites

Question 10

Axons carry information away from the cell body of the presynaptic cell in the form of _______.

Accepted Answer

The answer of Axons carry information away from the cell...

Question 11

Limb movement is controlled by sets of antagonistic muscles called flexors and extensors that work against one another.A sensory input to the motor neurons of these muscles will cause opposite effects.Why is this?

Accepted Answer

A)  The information is summed so that the flexor will contract first. 
B)  A monosynaptic spinal reflex will prevent one or the other muscle from contracting. 
C)  Interneurons are not part of the circuit. 
D)  When a muscle is stimulated to contract, an interneuron applies an inhibitory stimulus to the antagonistic muscle. 
E)  Information is transmitted to the brain, which decides which muscle is to contract. 
A)  The information is summed so that the flexor will contract first. 
B)  A monosynaptic spinal reflex will prevent one or the other muscle from contracting. 
C)  Interneurons are not part of the circuit. 
D)  When a muscle is stimulated to contract, an interneuron applies an inhibitory stimulus to the antagonistic muscle. 
E)  Information is transmitted to the brain, which decides which muscle is to contract.

Question 12

Which statement about acetylcholine receptors is false?

Accepted Answer

A)  The motor end plate contains both chemically gated and voltage-gated acetylcholine receptors. 
B)  They are proteins. 
C)  Binding of the neurotransmitter allows ion movement across the cell membrane. 
D)  They are found in the postsynaptic cell membrane of a neuromuscular junction. 
E)  Acetylcholine binds to them, opening their channels to sodium ions. 
A)  The motor end plate contains both chemically gated and voltage-gated acetylcholine receptors. 
B)  They are proteins. 
C)  Binding of the neurotransmitter allows ion movement across the cell membrane. 
D)  They are found in the postsynaptic cell membrane of a neuromuscular junction. 
E)  Acetylcholine binds to them, opening their channels to sodium ions.

Question 13

If the permeability of K+ channels in a neuron cell membrane increases, the membrane potential will become _______, compared with the resting state.

Accepted Answer

Question 14

Anesthetics and alcohol can permeate the blood-brain barrier because

Accepted Answer

A)  they are small molecules. 
B)  they are water-soluble. 
C)  they are lipid-soluble. 
D)  they pass through gated channels. 
E)  there are receptors for them on blood vessels. 
A)  they are small molecules. 
B)  they are water-soluble. 
C)  they are lipid-soluble. 
D)  they pass through gated channels. 
E)  there are receptors for them on blood vessels.

Question 15

Some drugs that are used to treat the nervous system act by modulating synaptic activity; drugs that enhance the effects of a neurotransmitter are known as _______, whereas those that block the effects of a neurotransmitter are called _______.

Accepted Answer

A)  hyperpolarizers; depolarizers 
B)  transmitters; blockers 
C)  ionotropic; metabotropic 
D)  chemical; electrical 
E)  agonists; antagonists 
A)  hyperpolarizers; depolarizers 
B)  transmitters; blockers 
C)  ionotropic; metabotropic 
D)  chemical; electrical 
E)  agonists; antagonists

Question 16

The part of the brain called the _______ would likely be relatively large in a vertebrate with complex movements associated with feeding and locomotion.

Accepted Answer

The answer of The part of the brain called the...

Question 17

If Na+ channels open and sodium ions diffuse into the cell,

Accepted Answer

A)  the cell will become hyperpolarized. 
B)  other sodium ions will move out of the cell. 
C)  voltage-gated channels will remain closed. 
D)  the inside of the cell will become less negative. 
E)  action potentials will be triggered. 
A)  the cell will become hyperpolarized. 
B)  other sodium ions will move out of the cell. 
C)  voltage-gated channels will remain closed. 
D)  the inside of the cell will become less negative. 
E)  action potentials will be triggered.

Question 18

The acetylcholine receptor is restored to its normal closed position by

Accepted Answer

A)  an action potential. 
B)  active transport of Na+ and K+. 
C)  the breakdown of acetylcholine by acetylcholinesterase. 
D)  exocytosis of acetylcholine. 
E)  closing of Ca2+ channels. 
A)  an action potential. 
B)  active transport of Na+ and K+. 
C)  the breakdown of acetylcholine by acetylcholinesterase. 
D)  exocytosis of acetylcholine. 
E)  closing of Ca2+ channels.

Question 19

Refer to the figure showing a neuromuscular junction.   At which of the numbered positions does the insecticide malathion exert its effects, and what will be the result?

Accepted Answer

Malathion inhibits acetylcholinesterase,

Question 20

Some nerve gases inhibit _______, causing acetylcholine to remain in the synaptic cleft, which causes spastic muscle contractions and death.

Accepted Answer

acetylchol

Exam 44: Neurons, Glia, and Nervous Systems

An advantage of an electrical synapse over a chemical synapse is that

Evaluate the following statement: Normally an action potential is propagated in two directions, toward the cell body and away from the cell body.

An action potential arriving at an axon terminal may cause release of a chemical messenger call a(n) _______.

Botulinum toxin impairs muscle contraction by acting on proteins that anchor vesicles in the presynaptic membrane.The toxin has medical uses.Given its effects at the neuromuscular junction, botulinum could be used to treat all of the following except

Giant neurons involved in the escape response of crayfish have _______ synapses, which allow rapid signal transmission.

Information about a sensory stimulus such as touch can be prevented from reaching the central nervous system by chemically blocking

Temporal summation adds up postsynaptic potentials that

Diseases that destroy myelin

Which of the following represents the correct order of the parts of neurons that are involved in the flow of information, beginning with the presynaptic cell and ending where a synapse is made with a postsynaptic cell?

Axons carry information away from the cell body of the presynaptic cell in the form of _______.

Limb movement is controlled by sets of antagonistic muscles called flexors and extensors that work against one another.A sensory input to the motor neurons of these muscles will cause opposite effects.Why is this?

Which statement about acetylcholine receptors is false?

If the permeability of K+ channels in a neuron cell membrane increases, the membrane potential will become _______, compared with the resting state.

Anesthetics and alcohol can permeate the blood-brain barrier because

Some drugs that are used to treat the nervous system act by modulating synaptic activity; drugs that enhance the effects of a neurotransmitter are known as _______, whereas those that block the effects of a neurotransmitter are called _______.

The part of the brain called the _______ would likely be relatively large in a vertebrate with complex movements associated with feeding and locomotion.

If Na+ channels open and sodium ions diffuse into the cell,

The acetylcholine receptor is restored to its normal closed position by

Refer to the figure showing a neuromuscular junction. At which of the numbered positions does the insecticide malathion exert its effects, and what will be the result?

Some nerve gases inhibit _______, causing acetylcholine to remain in the synaptic cleft, which causes spastic muscle contractions and death.

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

Filters

If the permeability of K⁺ channels in a neuron cell membrane increases, the membrane potential will become _______, compared with the resting state.

Some drugs that are used to treat the nervous system act by modulating synaptic activity; drugs that enhance the effects of a neurotransmitter are known as _, whereas those that block the effects of a neurotransmitter are called _.

If Na⁺ channels open and sodium ions diffuse into the cell,